Research On Conditional Privacy-protecting Authentication In Vehicular Ad Hoc Network

With the rapid development of Internet of Things technology,Vehicular ad hoc Network(VANET)has gradually become a research hotspot.In order to protect the security and privacy of VANET communication,researchers have proposed a number of Conditional Privacy-Protecting Authentication(CPPA)schemes.Most of the existing schemes can well meet their design requirements,but there is still room for improvement in terms of computing efficiency,communication efficiency,security,and practicability.In this paper,Identity-based Public Key Cryptosystem(ID-PKC)and Certificateless Public Key Cryptosystem(CL-PKC)CPPA are applied to solve some of the challenges faced by existing schemes.The main research results are as follows:1.We propose a new Generalized ring signcryption-based CPPA scheme.Most existing CPPA schemes provide only one function between signature and signcryption,which is hard to meet the requirements of complex application scenarios in reality.In addition,a CPPA scheme allows a trace authority to reveal the real identity of the sender in malicious messages,but it is hard to prove the authenticity of the tracking result.Therefore,we introduce the primitive of generalized ring signature to provide ring signature mode and ring signcryption mode in the same algorithm to deal with the different security requirements in complex application scenarios.We also design a convenient public verification algorithm to improve the credibility of the tracking results,so that the tracking results can be proved.2.We propose an efficient certificateless and paring-free CPPA scheme.CPPA schemes based on Tamper-Proof Device(TPD)is an important branch.Traditional TPD-based CPPA schemes usually assume that Private Key Generator(PKG)in the system is absolutely credible,which leads to well-known key escrow problems.In addition,most of these kinds of schemes require TPD to preload the system master private key,which undoubtedly increases the risk of master private key disclosure.The TPD in our scheme does not require preloading the master private key of the system,and it only preloads the vehicle’s own private key.In addition,our scheme enables vehicles to update their private keys in insecure channels,thus effectively resisting side-channel attacks.